When computer hardware is operated a vast majority of the electrical energy supplied to the hardware is converted into heat. In order to prevent computer hardware from over heating, it is common for the computer housings of desktop computers and computer server modules to include a cooling fan driven by a small electric motor that blows air through the computer housing assembly. During operation, heat generated by the computer hardware is transferred to the air conveyed through the housing assembly by the cooling fan.
Over the last ten or so years, desktop computers and computer server modules have progressively becoming more compact and more powerful and as a result, the amount of the heat being generated within a given volume of the computer housing assembly has increased. In order to prevent over heating of the computer hardware, the computer housing assemblies have been fitted with fans with larger blades, blades with more complex surfaces or fans that rotate at a higher revolution to increase the flow rate of the air through the computer housing.
A problem with modifying a cooling fan according to either of these approaches is that the noise created by the fan and thus emanating from the computer housing will also increase. In some instances, the noise created by the fan and emanating from the computer housing is at a level that is above acceptable occupational health and safety standards and hence, there is a need to reduce the level of noise.